Formulations for the removal of particles generated by cerium-containing solutions

ABSTRACT

Compositions and methods for removing lanthanoid-containing solids and/or species from the surface of a microelectronic device or microelectronic device fabrication hardware. Preferably, the lanthanoid-containing solids and/or species comprise cerium. The composition is preferably substantially devoid of fluoride ions.

FIELD

The present invention relates to compositions and methods for removinglanthanoid-containing solids and/or species from the surface of amicroelectronic device or microelectronic device fabrication hardware.Preferably, the compositions and methods remove cerium-containing solidsand/or species from surfaces.

DESCRIPTION OF THE RELATED ART

Resist, including photoresist, is a radiation sensitive (e.g., lightradiation sensitive) material used to form a patterned layer on asubstrate (e.g., a semiconductor wafer) during semiconductor devicefabrication. After exposing a portion of a resist coated substrate toradiation, either the exposed portion of the resist (for positiveresist), or the unexposed portion of the resist (for negative resist) isremoved to reveal the underlying surface of the substrate, leaving therest of the surface of the substrate coated and protected by resist.Resist may be more generally referred to as a masking material. Otherfabrication processes such as ion-implanting, etching, or depositing maybe performed on the uncovered surface of the substrate and the remainingresist. After performing the other fabrication processes, the remainingresist is removed in a strip operation.

In ion-implantation, dopant ions (e.g., ions of boron, boron difluoride,arsenic, indium, gallium, phosphorous, germanium, antimony, xenon orbismuth) are accelerated toward a substrate to be implanted. The ionsare implanted in the exposed regions of the substrate as well as in theremaining resist. Ion-implantation may be used, for example, to formimplanted regions in the substrate such as the channel region and sourceand drain regions of transistors. Ion-implantation may also be used toform lightly doped drain and double diffused drain regions. However,ions implanted in the resist may deplete hydrogen from the surface ofthe resist causing the resist to form an outer layer or crust, which maybe a carbonized layer that is harder than the underlying portion of theresist layer (i.e., the bulk portion of the resist layer). The outerlayer and the bulk portion have different thermal expansion rates andreact to stripping processes at different rates. High dose ion-implantedresist may cause severe hardening or crusting of the resist resulting inrelatively large differences between the outer layer and bulk portionin, for example, differences in thermal expansion rates, solubilitiesand other chemical and physical characteristics.

The present inventors previously discovered that a compositioncomprising at least one salt or coordination complex of the elementcerium, e.g., ceric ammonium nitrate (CAN), can effectively removemasking material, e.g., high dose ion-implanted resist, from asubstrate. Advantageously, this composition and method operates at alower acidity and temperature than the compositions and methods known inthe prior art and as such, causes less damage to TiN and other metalgate materials present on the substrate. Disadvantageously, thereduction of cerium (IV) compounds and sometimes the dilution of thesolution with water may result in precipitation of hydrolyzed solidssuch as Ce(NO₃)_(x)(OH)_(y), where x+y≦4, especially at elevatedtemperatures typically used for HDIS. In addition, hydrolyzed ceriumspecies may adsorb to films present on the substrate being treated.

It is an object of the present invention to substantially remove thehydrolyzed solids that may precipitate or adsorb on surfaces during theuse of lanthanoid-containing compositions.

SUMMARY OF THE INVENTION

The present invention relates to compositions and methods for removinglanthanoid-containing solids and/or species from the surface of amicroelectronic device or microelectronic device fabrication hardware.Preferably, the compositions and methods remove cerium-containing solidsand/or species from surfaces.

Other aspects, features and advantages of the invention will be morefully apparent from the ensuing disclosure and appended claims.

DETAILED DESCRIPTION, AND PREFERRED EMBODIMENTS THEREOF

The present invention relates to compositions and methods for removinglanthanoid-containing solids and/or species from the surface of amicroelectronic device or microelectronic device fabrication hardware.Preferably, the compositions and methods remove cerium-containing solidsand/or species from surfaces. The composition is preferablysubstantially devoid of fluoride ions.

In one aspect, a method of removing lanthanoid-containing solids and/orspecies from the surface of a microelectronic device or microfabricationhardware is described, said method comprising contacting the surfacewith a composition that substantially dissolves thelanthanoid-containing solids and/or species present on the surface.Preferably, the composition comprises at least one acid, at least onereducing agent, and water, wherein the composition is substantiallydevoid of fluoride ions.

For ease of reference, “microelectronic device” corresponds tosemiconductor substrates, flat panel displays, phase change memorydevices, solar panels and other products including solar cell devices,photovoltaics, and microelectromechanical systems (MEMS), manufacturedfor use in microelectronic, integrated circuit, energy collection, orcomputer chip applications. It is to be understood that the terms“microelectronic device,” “microelectronic substrate” and“microelectronic device structure” are not meant to be limiting in anyway and include any substrate or structure that will eventually become amicroelectronic device or microelectronic assembly. The microelectronicdevice can be patterned, blanketed, a control and/or a test device.

“Ion-implantation” is a process by which ions of a dopant material canbe implanted into target material, usually a solid. The physicalproperties of an ion-implanted material are usually different from thephysical properties of the target material prior to implantation.Ion-implantation is used in microelectronic device fabrication, forexample, in the fabrication of integrated circuits and siliconsemiconductor devices. The implanted ions may introduce or cause achemical change in the target due to the ions being a different elementthan the target, and/or a structural change, in that the target may bemodified, damaged or even destroyed by ion-implantation. By way ofexample only, elements that are typically used for implanted species insemiconductor fabrication include boron, boron difluoride, arsenic,indium, gallium, germanium, bismuth, xenon, phosphorus and antimony.Boron is a p-type dopant in silicon because it donates or causes a“hole” (i.e., electron vacancy) in the silicon. Arsenic is an n-typedopant in silicon because it donates or causes an extra electron in thesilicon. Dopants, such as boron and arsenic, implanted in intrinsicsilicon, may cause the intrinsic silicon to become conductive as asemiconductor. One or more dopant materials may be implanted into atarget material. Ion-implantation is usually characterized by dose andenergy. The dose is the number of ions that are implanted per area oftarget material. The energy is the energy of the ions being implanted.More advanced microelectronic device processing or fabricationtechnologies typically use higher dose and/or higher energy than oldertechnologies. In high dose ion-implantation (HDII), the ion dose may begreater than about 5×10¹⁴ ions/cm² and/or the average energy of theions, before the ions impact the target or substrate, may be from aboutfive thousand electron volts (KeV) to greater than 100 KeV.

“Resist” including photoresist (more generally, masking material) is aradiation sensitive material that is used to form a patterned coating ona surface, for example, the surface of a substrate or target. Resistsare used in the fabrication of microelectronic devices, for example,integrated circuits and silicon semiconductor devices. One use ofresists in the fabrication of semiconductor devices is as a mask forselective ion-implantation of dopants into a semiconductor substrate. Alayer of resist is applied to the surface of the semiconductorsubstrate, or to the surface of a layer on or within the substrate, suchas an insulator layer above a semiconductor layer. A portion of theresist is exposed to the radiation, such portion of the resistcorresponding to either the area of the semiconductor to be implanted(positive resist) or to the area of the semiconductor not to beimplanted (negative resist). The resist is then exposed to a developerwhich assists in removing a portion of the resist so that only thedesired portion of the resist remains. Ion-implantation occurs after theresist is patterned by exposure to the radiation and developed by thedeveloper. The remaining portion of the resist blocks the implanted ionsfrom reaching the microelectronic device, or other material, below theresist. The ions blocked by the resist are implanted into the resistinstead of the underlying substrate. The portions of the microelectronicdevice not covered by resist are ion-implanted. Because of therelatively high dose and/or high energy of the implanted ions blocked bythe resist, the resist forms a crust or hard shell on the outer portionsor outer sides of the resist where the ions impact and are absorbed. Theresist hardening may result from, or be referred to as, carbonization,polymerizing or polymer cross-linking. The crust is known to bedifficult to remove during a resist stripping process (e.g., the crustis insoluble in some known solvents used for stripping). The thicknessof the resist crust is dependent upon the dosage of the implanted ionsand the ion-implant energy. The resist material that is inside orbeneath the crust, that is, the portion of the resist that is generallyunaffected by the ions, is referred to as bulk resist or bulk resistmaterial.

“High dose ion-implantation strip” (HDIS) is the process of strippingexposed resist that has received HDII. Some HDIS processes may includedry processes, such as plasma processes and vacuum processes.Characteristics of an HDIS process may include, for example, strip rate,amount of residue, and loss of the exposed and underlying layer, such asthe substrate, silicon substrate or layers above silicon. Residues aresometimes found on the substrate surface after an HDIS. The residues mayresult from, for example, sputtering during HDII, incomplete removal ofthe outer layer of resist, and/or oxidation of implanted ions in theresist. Optimally, after stripping and, optionally, rinsing, the surfaceshould be substantially residue free to ensure high yield and eliminatethe need for additional residue removal processing.

As defined herein, the “surface” comprises at least silicon, a metalgate material, or both, for example, TiN comprised in a metal gate of anfield-effect transistor (FET) or TiN comprised in a barrier between asemiconductor and a metal. Silicon is comprised in silicon-on-insulator(SOI) wafers that may be used, for example, as substrates or part of asubstrate for electronic devices such as FETs and integrated circuits.“Silicon” may be defined to include, Si, polycrystalline Si,monocrystalline Si, and SiGe. Other forms of “silicon” may includesilicon-containing materials such as silicon oxide, thermal oxide, SiOHand SiCOH.

As defined herein, “metal gate material” corresponds to materials havinga Fermi level corresponding to the mid-gap of the semiconductorsubstrate such as Ti, Ta, W, Mo, Ru, Al, La, titanium nitride, tantalumnitride, tantalum carbide, titanium carbide, molybdenum nitride,tungsten nitride, ruthenium (IV) oxide, tantalum silicon nitride,titanium silicon nitride, tantalum carbon nitride, titanium carbonnitride, titanium aluminide, tantalum aluminide, titanium aluminumnitride, tantalum aluminum nitride, lanthanum oxide, or combinationsthereof. It should be appreciated that the compounds disclosed as metalgate materials may have varying stoichiometries. Accordingly, titaniumnitride will be represented as TiN_(x) herein, tantalum nitride will berepresented as TaN_(x) herein, and so on.

As used herein, “about” is intended to correspond to ±5% of the statedvalue.

“Substantially devoid” is defined herein as less than 2 wt. %,preferably less than 1 wt. %, more preferably less than 0.5 wt. %, evenmore preferably less than 0.1 wt. %, and most preferably 0 wt.%.

As used herein, “to remove” means that material is dissolved orotherwise solubilized in the composition, preferably dissolved.

As used herein, “post-CMP residue” corresponds to particles from thepolishing slurry, e.g., silica-containing particles, chemicals presentin the slurry, reaction by-products of the polishing slurry, carbon-richparticles, polishing pad particles, brush deloading particles, equipmentmaterials of construction particles, copper, copper oxides,copper-containing materials, aluminum, aluminum oxides,aluminum-containing materials, organic residues, and any other materialsthat are the by-products of the CMP process.

As used herein, “post-etch residue” corresponds to material remainingfollowing gas-phase plasma etching processes, e.g., BEOL dual damasceneprocessing. The post-etch residue may be organic, organometallic,organosilicic, or inorganic in nature, for example, silicon-containingmaterial, carbon-based organic material, and etch gas residue such asoxygen and fluorine.

As defined herein, “post-ash residue,” as used herein, corresponds tomaterial remaining following oxidative or reductive plasma aching toremove hardened photoresist and/or bottom anti-reflective coating (BARC)materials. The post-ash residue may be organic, organometallic,organosilicic, or inorganic in nature.

Compositions of the invention may be embodied in a wide variety ofspecific formulations, as hereinafter more fully described.

In all such compositions, wherein specific components of the compositionare discussed in reference to weight percentage ranges including a zerolower limit, it will be understood that such components may be presentor absent in various specific embodiments of the composition, and thatin instances where such components are present, they may be present atconcentrations as low as 0.001 weight percent, based on the total weightof the composition in which such components are employed.

The present invention relates to a composition and method of use whereinthe composition can be used to safely remove hydrolyzedlanthanoid-containing solids and species, e.g., hydrolyzedcerium-containing solids and species, from a substrate having samethereon. As previously discussed, the reduction of lanthanoid-containingcompounds and sometimes the dilution of the solution with water mayresult in precipitation of hydrolyzed solids such asCe(NO₃)_(x)(OH)_(y), where x+y≦4, especially at elevated temperaturestypically used for HDIS. In addition, hydrolyzed lanthanoid-containingspecies, which are ionic or molecular in nature, may adsorb to filmspresent on the surface being treated. Lanthanoid elements are generallyknown to be those elements with atomic numbers 57 through 71, i.e.,lanthanum, cerium, praseodymium, neodymium, promethium, samarium,europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium,ytterbium, and lutetium. Hereinafter, “lanthanoid-containing solids” and“lanthanoid-containing species” correspond to solids that comprise alanthanoid element which precipitate on the surface as a result ofreduction of the lanthanoid element, dilution of the compositioncomprising the lanthanoid element, or both, or otherwise adsorb to thesurface.

In a first aspect, a method of removing lanthanoid-containing solidsfrom the surface of a microelectronic device is described, said methodcomprising contacting the surface with a composition that substantiallydissolves the lanthanoid-containing solids relative to the surface.Typically, the lanthanoid-containing solids will be present asparticulate matter. Accordingly, “substantial dissolution” correspondsto the dissolution of at least 95% of the volume of the particlerelative to the particle prior to contact with the composition, morepreferably at least 98%, even more preferably at least 99%, and mostpreferably at least 99.9% of the volume of the particle relative to theparticle prior to contact with the composition. Preferably, theselectivity of the composition for the lanthanoid-containing solidsrelative to the surface is at least about 100:1 lanthanoid-containingsolid relative to surface, more preferably at least about 1000:1, evenmore preferably at least about 10000:1, and most preferably at leastabout 100000:1. Considered another way, the surface should not besubstantially removed (i.e., dissolve, erode, etc.) by the compositionwhile the lanthanoid-containing solids should be substantially removed.Preferably, the lanthanoid-containing solid comprises cerium.

In a second aspect, a method of removing lanthanoid-containing speciesfrom the surface of a microelectronic device is described, said methodcomprising contacting the surface with a composition that substantiallyremoves the lanthanoid-containing species from the surface, wherein thelanthanoid-containing species are adsorbed at the surface prior tocontact of the surface with the composition. Preferably, the surface isnot substantially affected by the composition, meaning that the surfacedoes not undergo substantial dissolution or erosion in the presence ofthe composition. As defined herein, “adsorption” corresponds to theadhesion of the lanthanoid-containing species at a surface and can becharacterized as physisorption (physical adsorption characterized byweak van der Waals forces) or chemisorption (chemical adsorption drivenby a chemical reaction occurring at a surface). Preferably, thelanthanoid-containing species comprises cerium.

In a third aspect, a method of removing lanthanoid-containing speciesand/or solids from microfabrication hardware is described, said methodcomprising contacting the surface of the hardware with a compositionthat substantially removes the lanthanoid-containing species and/orsolids from the surface. Typically, the lanthanoid-containing solidswill be present as particulate matter and the lanthanoid-containingspecies are adsorbed at the surface. Microfabrication hardware includes,but is not limited to, hardware used during photolithography that isexposed to compositions comprising lanthanoids. The materialconstruction of the microfabrication hardware may be metal, plastic,glass, porcelain, or a mineral. Preferably, the lanthanoid comprisescerium and the lanthanoid-containing solid and/or species comprisecerium.

The methods of the first, second and third aspects are carried out attemperature in a range from about room temperature to about 100° C.,preferably about room temperature to about 80° C., and most preferablyabout room temperature to about 60° C. It should be appreciated by theskilled artisan that the time of removal varies depending on whether theremoval is performed in a single wafer tool or a multiple wafer tool orlanthanoid-containing species and/or solid is removed from hardware. Fora single wafer tool, time is preferably in a range from about 10 sec toabout 10 minutes, preferably about 20 sec to about 5 minutes, and for amultiple wafer tool or hardware, time is preferably in a range fromabout 1 minute to about 1000 minutes. Such contacting times andtemperatures are illustrative, and any other suitable time andtemperature conditions may be employed that are efficacious to removecerium-containing solids and/or species from a surface.

In removal application from a surface of a microelectronic device, thecomposition is applied in any suitable manner to the device, e.g., byspraying the composition on the surface of the device, by dipping thedevice in a static or dynamic volume of the composition, by contactingthe device with another material, e.g., a pad, or fibrous sorbentapplicator element, that has the composition absorbed thereon, or by anyother suitable means, manner or technique by which the composition isbrought into contact with the surface having the cerium-containingsolids and/or species thereon. Further, batch or single wafer processingis contemplated herein. In removal application from hardware, thecomposition is applied in any suitable manner to the hardware, e.g., byspraying the composition on the surface of the hardware, by dipping thehardware in a static or dynamic volume of the composition, by contactingthe hardware with another material, e.g., a pad, or fibrous sorbentapplicator element, that has the composition absorbed thereon, or by anyother suitable means, manner or technique by which the composition isbrought into contact with the hardware having the cerium-containingsolids and/or species thereon.

Following the achievement of the desired removal action, the compositionis readily removed from the surface of the device or the hardware towhich it has previously been applied, e.g., by rinse, wash, or otherremoval step(s), as may be desired and efficacious. For example, thedevice or hardware may be rinsed with a rinse solution includingdeionized water and/or dried (e.g., spin-dry, N₂, solvents (such as IPA)vapor-dry etc.).

In a fourth aspect, a composition to remove lanthanoid-containing solidsand/or species is described, said composition including at least oneacid and at least one reducing agent. In one embodiment, the compositioncomprises, consists of or consists essentially of at least one strongacid, at least one reducing agent, optionally at least one salt of theat least one strong acid, and water, with the proviso that thecomposition is substantially devoid of fluoride ions and when the atleast one strong acid is nitric acid and the at least one reducing agentis hydrogen peroxide, the composition is substantially devoid of (i)boric acid and (ii) an organic acid having an active carboxylic acidgroup such as tartaric acid, citric acid, lactic acid, gluconic acid andedetic acid. In another embodiment, the composition comprises, consistsof or consists essentially of at least one weak acid, at least onereducing agent, and water, with the proviso that the composition issubstantially devoid of fluoride ions. Preferably, the composition doesnot substantially remove metal gate material present on the substrate.The water is preferably deionized. Preferably, the composition is usedin the methods of the first through third aspects described herein.

The pH of the composition of the fourth aspect is in a range from about0 to about 4, preferably about 1 to about 3.5. When titanium nitridelayers are present, preferably the pH of the composition is greater thanor equal to 2 and less than 4.

The at least one strong acid is selected from the group consisting ofnitric acid, sulfuric acid, perchloric acid, hydrochloric acid,hydrobromic acid, hydroiodic acid, methanesulfonic acid, andcombinations thereof. Preferably, the at least one strong acid comprisessulfuric acid, nitric acid, or a combination of nitric and sulfuricacid, even more preferably sulfuric acid. The amount of the at least onestrong acid is preferably in a range from about 0.1 wt % to about 15 wt%, preferably about 0.1 wt % to about 5 wt %, and most preferably about0.5 wt % to about 2.5 wt %, based on the total weight of thecomposition.

The at least one reducing agent includes, but is not limited to,hydrogen peroxide, ascorbic acid, borane complexes such asborane-pyridine or borane-morpholine, hydroxylamine sulfate,hydroxylamine hydrochloride, ammonium nitrite, ammonium sulfite,ammonium hydrogen sulfite, hydrazine sulfate, hydrazine hydrochloride,ammonium hydrogen sulfide, diethyl malonate, hydroquinone, ammoniummetabisulfite, polyphenon 60, glucose, ammonium citrate, hydrogen,formic acid, oxalic acid, acetaldehyde, hydrogen iodide, ammoniumphosphite, ammonium hydrogen phosphite, hypophosphorous acid, andcombinations thereof. The above mentioned “ascorbic acid” refers to notonly ascorbic acid itself (reduced-form) but also dehydroascorbic acid(oxidized-form), xyloascorbic acid, arabo-ascorbic acid, optical isomersof both the L-isomer and D-isomer, and esters of ascorbic acid.Preferably, the at least one reducing agent comprises ascorbic acid orhydrogen peroxide, preferably ascorbic acid. The amount of the at leastone reducing agent is preferably in a range from about 0.1 wt % to about10 wt %, preferably about 0.1 wt % to about 5 wt %, and most preferablyabout 0.1 wt % to about 2 wt %, based on the total weight of thecomposition.

When present, the salt of the at least one strong acid corresponds to asodium, potassium, tetramethylammonium, or preferably ammonium salt ofthe conjugate base of the at least one strong acid. For example, if thestrong acid comprises sulfuric acid, the salt of the at least one strongacid can be sodium sulfate, potassium sulfate, tetramethylammoniumsulfate, ammonium sulfate, or the like. When present, the amount of saltof the at least one strong acid is preferably in a range from about 0.1to about 10 wt %, preferably about 0.5 to about 5 wt %, based on thetotal weight of the composition.

Accordingly, the components of the composition comprising, consisting ofor consisting essentially of at least one strong acid, at least onereducing agent, optionally at least one salt of the at least one strongacid, and water, with the proviso that the composition is substantiallydevoid of fluoride ions and when the at least one strong acid is nitricacid and the at least one reducing agent is hydrogen peroxide, thecomposition is substantially devoid of (i) boric acid and (ii) anorganic acid having an active carboxylic acid group such as tartaricacid, citric acid, lactic acid, gluconic acid and edetic acid, arepresent in the following amounts:

more most component preferably preferably preferably alternative strongabout 0.1 about 0.1 about 0.5 about 0.5 acid(s) to about to about toabout to about 15 wt % 5 wt % 2.5 wt % 2.5 wt % reducing about 0.1 about0.1 about 0.1 about 0.1 agent(s) to about to about to about to about 10wt % 5 wt % 2 wt % 2 wt % salt of 0 0 0 0.5 strong to about to about toabout to about acid 10 wt % 10 wt % 10 wt % 5 wt % water about 65 about80 about 90.5 about 85.5 to about to about to about to about 99.8 wt %99.8 wt % 98.9 wt % 99.4 wt %

For the purposes of the present disclosure, a “weak acid” preferably hasa pKa in a range from about 1.5 to about 4. Weak acids include, but arenot limited to, nitrous acid, phosphorous acid, hydrogen bisulfate,hydrogen selenite, phosphoric acid, cyanic acid, formic acid, glycericacid, glycolic acid, glyoxylic acid, lactic acid, pyruvic acid, mandelicacid, succinic acid, malonic acid, and combinations thereof. Preferably,the at least one weak acid comprises formic acid. The amount of the atleast one weak acid is preferably in a range from about 0.1 wt % toabout 15 wt %, preferably about 0.1 wt % to about 5 wt %, and mostpreferably about 1 wt % to about 5 wt %, based on the total weight ofthe composition.

Accordingly, the components of the composition comprising, consisting ofor consisting essentially of at least one weak acid, at least onereducing agent, and water, with the proviso that the composition issubstantially devoid of fluoride ions, are present in the followingamounts:

more most component preferably preferably preferably weak about 0.1about 0.1 about 1 acid(s) to about to about to about 15 wt % 5 wt % 5 wt% reducing about 0.1 about 0.1 about 0.1 agent(s) to about to about toabout 10 wt % 5 wt % 2 wt % water about 75 about 90 about 93 to about toabout to about 99.8 wt % 99.8 wt % 98.9 wt %

In a preferred embodiment, the composition of the fourth aspectcomprises, consists of, or consists essentially of nitric acid, ascorbicacid, and water. In another embodiment, the composition of the fourthaspect comprises, consists of, or consists essentially of sulfuric acid,ascorbic acid, and water. In still another embodiment, the compositionof the fourth aspect comprises, consists of, or consists essentially ofhydrochloric acid, ascorbic acid, and water. In yet another embodiment,the composition of the fourth aspect comprises, consists of, or consistsessentially of formic acid, ascorbic acid, and water. Still anotherembodiment of the fourth aspect is a composition comprising, consistingof, or consisting essentially of malonic acid, ascorbic acid, and water.In another embodiment, the composition of the fourth aspect comprises,consists of, or consists essentially of sulfuric acid, ammonium sulfate,ascorbic acid, and water. In each embodiment, the composition issubstantially devoid of fluoride ions.

The composition of the fourth aspect can further comprise at least onereduced lanthanoid species, e.g., cerium (III) species, solubilizedtherein. Accordingly, in another embodiment, the composition comprises,consists of or consists essentially of at least one strong acid, atleast one reducing agent, at least one reduced lanthanoid species,optionally at least one salt of the at least one strong acid, and water,with the proviso that the composition is substantially devoid offluoride ions and when the at least one strong acid is nitric acid andthe at least one reducing agent is hydrogen peroxide, the composition issubstantially devoid of (i) boric acid and (ii) an organic acid havingan active carboxylic acid group such as tartaric acid, citric acid,lactic acid, gluconic acid and edetic acid. In yet another embodiment,the composition comprises, consists of or consists essentially of atleast one weak acid, at least one reducing agent, at least one reducedlanthanoid species, and water, with the proviso that the composition issubstantially devoid of fluoride ions.

It will be appreciated that it is common practice to make concentratedforms of the compositions to be diluted prior to use. For example, thecomposition may be manufactured in a more concentrated form, includingat least one strong acid, at least one reducing agent, optionally atleast one salt of the at least one strong acid, and water, with theproviso that the composition is substantially devoid of fluoride ionsand when the at least one strong acid is nitric acid and the at leastone reducing agent is hydrogen peroxide, the composition issubstantially devoid of (i) boric acid and (ii) an organic acid havingan active carboxylic acid group such as tartaric acid, citric acid,lactic acid, gluconic acid and edetic acid, and thereafter diluted withwater at the manufacturer, before use, and/or during use at the fab. Inanother embodiment, the composition may comprise, consist of or consistessentially of at least one weak acid, at least one reducing agent, atleast one reduced lanthanoid species, and water, with the proviso thatthe composition is substantially devoid of fluoride ions, and thereafterdiluted with water at the manufacturer, before use, and/or during use atthe fab. Dilution ratios may be in a range from about 0.1 part diluent:1part composition concentrate to about 100 parts diluent:1 partcomposition concentrate.

The compositions of the invention are easily formulated by simpleaddition of the respective ingredients and mixing to homogeneouscondition. Furthermore, the compositions may be readily formulated assingle-package formulations or multi-part formulations that are mixed ator before the point of use, preferably multi-part formulations. Theindividual parts of the multi-part formulation may be mixed at the toolor in a mixing region/area such as an inline mixer or in a storage tankupstream of the tool. It is contemplated that the various parts of themulti-part formulation may contain any combination ofingredients/constituents that when mixed together form the desiredcomposition. The concentrations of the respective ingredients may bewidely varied in specific multiples of the composition, i.e., moredilute or more concentrated, and it will be appreciated that thecompositions described herein can variously and alternatively comprise,consist or consist essentially of any combination of ingredientsconsistent with the disclosure herein.

Accordingly, a fifth aspect relates to a kit including, in one or morecontainers, one or more components adapted to form the compositionsdescribed herein. Preferably, the kit includes, in one or morecontainers, at least one strong acid, at least one reducing agent,optionally at least one salt of the at least one strong acid, andoptionally water, for combining with water at the fab or the point ofuse. Optionally, the containers of the kit may include at least one weakacid, at least one reducing agent, and optionally water, for combiningwith water and/or oxidizing agent(s) at the fab or the point of use. Thecontainers of the kit must be suitable for storing and shipping saidremoval compositions, for example, NOWPak® containers (AdvancedTechnology Materials, Inc., Danbury, Conn., USA). The one or morecontainers which contain the components of the composition preferablyinclude means for bringing the components in said one or more containersin fluid communication for blending and dispense. For example, referringto the NOWPak® containers, gas pressure may be applied to the outside ofa liner in said one or more containers to cause at least a portion ofthe contents of the liner to be discharged and hence enable fluidcommunication for blending and dispense. Alternatively, gas pressure maybe applied to the head space of a conventional pressurizable containeror a pump may be used to enable fluid communication. In addition, thesystem preferably includes a dispensing port for dispensing the blendedremoval composition to a process tool.

Substantially chemically inert, impurity-free, flexible and resilientpolymeric film materials, such as high density polyethylene, arepreferably used to fabricate the liners for said one or more containers.Desirable liner materials are processed without requiring co-extrusionor barrier layers, and without any pigments, UV inhibitors, orprocessing agents that may adversely affect the purity requirements forcomponents to be disposed in the liner. A listing of desirable linermaterials include films comprising virgin (additive-free) polyethylene,virgin polytetrafluoroethylene (PTFE), polypropylene, polyurethane,polyvinylidene chloride, polyvinylchloride, polyacetal, polystyrene,polyacrylonitrile, polybutylene, and so on. Preferred thicknesses ofsuch liner materials are in a range from about 5 mils (0.005 inch) toabout 30 mils (0.030 inch), as for example a thickness of 20 mils (0.020inch).

Regarding the containers for the kits, the disclosures of the followingpatents and patent applications are hereby incorporated herein byreference in their respective entireties: U.S. Pat. No. 7,188,644entitled “APPARATUS AND METHOD FOR MINIMIZING THE GENERATION OFPARTICLES IN ULTRAPURE LIQUIDS;” U.S. Pat. No. 6,698,619 entitled“RETURNABLE AND REUSABLE, BAG-IN-DRUM FLUID STORAGE AND DISPENSINGCONTAINER SYSTEM;” and PCT/US08/63276 entitled “SYSTEMS AND METHODS FORMATERIAL BLENDING AND DISTRIBUTION” filed on May 9, 2008 in the name ofAdvanced Technology Materials, Inc.

A sixth aspect of the invention relates to the removal of post-etchresidue, post-ash residue, post-chemical mechanical polishing residue,and other contaminants and/or by-products of the microelectronic devicemanufacturing process, said method comprising contacting a surface of amicroelectronic device having said residue, contaminants and/orby-products thereon with a composition of the fourth aspect tosubstantially remove said residue, contaminants and/or by-products fromthe surface.

Another aspect relates to the improved microelectronic devices madeaccording to the methods of the invention and to products containingsuch microelectronic devices.

A still further aspect relates to methods of manufacturing an articlecomprising a microelectronic device, said method comprising contacting asurface of the microelectronic device with a composition for sufficienttime to substantially dissolve lanthanoid-containing solids and/orspecies from the surface, and incorporating said microelectronic deviceinto said article. Preferably, the lanthanoid comprises cerium.

Yet another aspect relates to an article of manufacture comprising acomposition and a surface comprising lanthanoid-containing solids and/orspecies, wherein the composition comprises, consists of or consistsessentially of at least one strong acid, at least one reducing agent,optionally at least one salt of the at least one strong acid, and water,with the proviso that the composition is substantially devoid offluoride ions and when the at least one strong acid is nitric acid andthe at least one reducing agent is hydrogen peroxide, the composition issubstantially devoid of (i) boric acid and (ii) an organic acid havingan active carboxylic acid group such as tartaric acid, citric acid,lactic acid, gluconic acid and edetic acid. Alternatively, thecomposition comprises, consists of or consists essentially of at leastone weak acid, at least one reducing agent, and water, with the provisothat the composition is substantially devoid of fluoride ions.

Another aspect relates to a method for removing photoresist from asurface, said method comprising contacting the photoresist with asolution comprising cerium to substantially remove the photoresist, andcontacting the surface with a composition that substantially removes thelanthanoid-containing species present on the surface. Prior tocontacting the photoresist with the solution, it is assumed that thephotoresist has been ion-implanted by greater than approximately 5×10¹⁴ions per square centimeter, and/or ions having an average energy, beforethe ions impact the photoresist, greater than approximately fivethousand electron volts (5 KeV). Preferably, the surface comprises TiN.Preferably, the solution used to remove the resist or photoresistcomprises cerium ammonium nitrate. Preferably, the composition thatsubstantially removes the lanthanoid-containing species is one of thecompositions of the fourth aspect described herein.

In another aspect, a method for removing a masking material isdescribed, the method comprising: contacting the masking material with asolution comprising cerium and contacting the surface with a compositionthat substantially removes the lanthanoid-containing species present onthe surface, wherein the masking material is comprised within a layerformed on at least a first portion of a surface, and wherein the maskingmaterial blocks at least a first portion of dopant material fromcontacting the at least a first portion of the surface, and wherein thefirst portion of the dopant material comprises ions implanted into themasking material. Ions implanted into the masking material can compriseat least one of: boron; boron trifluoride; indium; gallium; thallium;germanium; bismuth; arsenic; phosphorus; xenon and antimony. Preferably,the solution used to remove the resist or photoresist comprises ceriumammonium nitrate. Preferably, the composition that substantially removesthe lanthanoid-containing species is one of the compositions of thefourth aspect described herein.

Still another aspect relates to the removal of manganese oxide particlesfrom the surface of microfabrication hardware, said method comprisingcontacting the surface of the hardware with a composition thatsubstantially removes the manganese oxide particles from the surface.Manganese oxide particles are often the byproduct of a composition thatincludes permanganate, whether present as a permanganate salt orgenerated in situ, wherein the manganese oxide particles deposit on thesurface of the microfabrication hardware as well as on wafers. It wassurprisingly discovered that the compositions described herein, areeffective at dissolving these manganese-containing precipitates underthe process conditions described herein to remove lanthanum-containingspecies.

The features and advantages of the invention are more fully illustratedby the following non-limiting examples, wherein all parts andpercentages are by weight, unless otherwise expressly stated.

EXAMPLE 1

To test the capability of various solutions to dissolveCe(IV)-containing precipitates, the precipitates were generated byheating a 20% cerium ammonium nitrate (CAN) solution in deionized waterat 70° C. for 20 hours. A substantial amount of yellow precipitate wasformed and settled at the bottom of the bottle. The solution wasdecanted, leaving behind a slurry of precipitate in residual CANsolution. The dissolution of 0.05-0.1 ml of the slurry was then testedat room temperature in test tubes, in the presence of 3-6 ml water, someacid, and some reducing agent. The mixture was shaken vigorously in thecapped test tube for 0.5-2 minutes and then periodically as needed. Thedissolution was considered successful if the solution was colorless andclear within 1 minute; however, it should be understood that much longerprocess times and/or temperatures higher than ambient may be acceptable.

-   Solution 1: 0.2 g ascorbic acid, 4 g dilute HNO₃ (1 part by weight    of conc. HNO₃:3 parts by weight water, hereinafter the “1:3 HNO₃    solution”), 0.1 mL slurry. The original dark color and turbidity    disappears in less than 1 min. Two additional 0.1 mL slurry    additions were quickly dissolved as well.-   Solution 2: 0.2 g ascorbic acid, 4 g water, 0.1 mL slurry. No    obvious effect. After adding 1 g of 1:3 HNO₃ and shaking, the    turbidity and color quickly disappeared.-   Solution 3: 0.1 g ascorbic acid, 4 g water, 1 g 1:3 HNO₃, 0.1 mL    slurry. All turbidity and color disappeared within 80 sec.-   Solution 4: 0.1 g ascorbic acid, 3.6 g water, 0.5 g 4 M H₂SO₄, 0.1    mL slurry. All turbidity and color disappeared within 20 sec.-   Solution 5: 0.11 g ascorbic acid, 4.9 g water, 0.1 g 95% H₂SO₄, 0.1    mL slurry. All turbidity and color disappeared within 40 sec.-   Solution 6: 0.05 g ascorbic acid, 4.9 g water, 0.1 g 95 wt % H₂SO₄,    0.05 mL slurry. All turbidity and color disappeared within 30 sec.    When another 0.05 mL slurry was added, all turbidity and color    disappeared within 40 sec.-   Solution 7: 0.05 g ascorbic acid, 2 g 1 M HCl, 3 g water, 0.05 mL    slurry. The dark brown color faded slowly and was clear after 4 min.-   Solution 8: 0.060 g ascorbic acid, ˜5 g water, 0.110 g 95% H₂SO₄,    0.189 g (NH₄)₂SO₄, water to obtain a total of 6 g, mix, and then 0.1    mL slurry. No dark color observed, but turbidity disappears after    about 1 minute. Note that this mixture is part NH₄HSO₄, part    (NH₄)₂SO₄.-   Solution 9: 0.055 g ascorbic acid, 5.9 g water, 0.24 g 95% formic    acid, 0.06 mL slurry. All turbidity and color disappeared within 30    sec of shaking.-   Solution 10: 5.9 g water, 0.24 g 95% formic acid, 0.06 mL slurry. No    significant dissolution in ˜3 minutes, but following the addition of    ˜50 mg ascorbic acid, rapid dissolution occurred (˜30 sec).-   Solution 11: 0.05 g ascorbic acid, 0.25 g malonic acid, 4.7 g water,    0.05 mL slurry. The solution initially was a light brown color,    which cleared after about 7 min.

Although not wishing to be bound by theory, these examples suggest thatthe presence of an acid stronger than ascorbic acid is useful for thespeedy dissolution of Ce(IV)-containing particles. The solutions, whichwere devoid of fluoride, were effective at dissolving theCe(IV)-containing particles even at room temperature without damagingthe surface.

Although the invention has been variously disclosed herein withreference to illustrative embodiments and features, it will beappreciated that the embodiments and features described hereinabove arenot intended to limit the invention, and that other variations,modifications and other embodiments will suggest themselves to those ofordinary skill in the art, based on the disclosure herein. The inventiontherefore is to be broadly construed, as encompassing all suchvariations, modifications and alternative embodiments within the spiritand scope of the claims hereafter set forth.

1. A method of removing lanthanoid-containing solids and/or species fromthe surface of a microelectronic device or microfabrication hardware,said method comprising contacting the surface with a composition thatsubstantially dissolves the lanthanoid-containing solids and/or speciespresent on the surface.
 2. The method of claim 1, wherein thelanthanoid-containing solids are particulate matter present on thesurface.
 3. The method of claim 2, wherein the selectivity of thecomposition for the lanthanoid-containing solids and/or species relativeto the surface is at least about 100:1.
 4. The method of claim 1,wherein the lanthanoid-containing species are ionic or molecular innature and are adsorbed onto the surface of the microelectronic deviceor microfabrication hardware.
 5. The method of claim 1, wherein thelanthanoid-containing solids and/or species comprises at least onespecies selected from the group consisting of lanthanum, cerium,praseodymium, neodymium, promethium, samarium, europium, gadolinium,terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.6. The method of claim 1 The method of any of the preceding claims,wherein the lanthanoid-containing solids and/or species comprisescerium.
 7. The method of claim 6, wherein the lanthanoid-containingsolids and/or species comprise Ce(IV).
 8. The method of claim 1, whereintemperature is in a range from about room temperature to about 100° C.for time in a range from about 10 sec to about 60 minutes.
 9. (canceled)10. (canceled)
 11. The method of claim 1, said method furthercomprising, prior to contacting the surface with the composition thatsubstantially dissolves the lanthanoid-containing solids and/or species,contacting the surface of the microelectronic device with a resistremoval composition comprising at least one salt or coordination complexof a lanthanoid element to remove resist from said surface.
 12. Themethod of claim 11, wherein the resist removal composition comprisescerium.
 13. The method of claim 11, wherein the resist removalcomposition comprises cerium ammonium nitrate.
 14. The method of claim1, wherein the composition comprises at least one acid, at least onereducing agent, and water, wherein the composition is substantiallydevoid of fluoride ions.
 15. The method of claim 1, wherein the pH ofthe composition is in a range from about 0 to about
 4. 16. The method ofclaim 14, wherein the at least one reducing agent comprises hydrogenperoxide, ascorbic acid, borane-pyridine, borane-morpholine,hydroxylamine sulfate, hydroxylamine hydrochloride, ammonium nitrite,ammonium sulfite, ammonium hydrogen sulfite, hydrazine sulfate,hydrazine hydrochloride, ammonium hydrogen sulfide, diethyl malonate,hydroquinone, ammonium metabisulfite, polyphenon 60, glucose, ammoniumcitrate, hydrogen, formic acid, oxalic acid, acetaldehyde, hydrogeniodide, ammonium phosphite, ammonium hydrogen phosphite, hypophosphorousacid, and combinations thereof.
 17. The method of claim 14, wherein theat least one reducing agent comprises ascorbic acid.
 18. The method ofclaim 14, wherein the at least one acid comprises at least one strongacid or at least one weak acid.
 19. The method of claim 18, wherein theat least one strong acid comprises a species selected from the groupconsisting of nitric acid, sulfuric acid, perchloric acid, hydrochloricacid, hydrobromic acid, hydroiodic acid, methanesulfonic acid, andcombinations thereof.
 20. The method of claim 18, wherein the at leastone strong acid comprises sulfuric acid.
 21. The method of claim 18,wherein the composition further comprises the salt of the at least onestrong acid.
 22. (canceled)
 23. The method of claim 18, wherein the atleast one weak acid comprises a species selected from the groupconsisting of nitrous acid, phosphorous acid, hydrogen bisulfate,hydrogen selenite, phosphoric acid, cyanic acid, formic acid, glycericacid, glycolic acid, glyoxylic acid, lactic acid, pyruvic acid, mandelicacid, succinic acid, malonic acid, and combinations thereof.